Is there a way to use a Joystick in this game on PC?

There most certainly is! If it's the original Dark Forces you're talking about, first make sure your device is recognised by DOSBox. You might want to use "joysticktype=4axis" or "joysticktype=4axis_2" as your DOSBox startup option, because that will prevent DOSBox from doing its axis splitting weirdness when more devices are connected. Next I'd recommend to unmap the buttons in the Dark Forces' INSTALL.EXE (leave or adjust the axis mapping) and map the buttons to the desired keyboard keys either within DOSBox Keymapper (Ctrl-F1) or, better yet, 3rd party software like Joy2Key or UCR (Universal Control Remapper - my personal favourite). That way, you will get around the silly DOS limits (it allows only the use of 4 buttons and 4 axis). Finally, launch Dark Forces, enable joystick in the pause menu, calibrate it if necessary and enjoy!